Polyols are converted to propylene glycol and/or ethylene glycol through a hydrogenolysis reaction. In such reaction, the polyols are converted through a catalytic operation to the desired propylene glycol and/or ethylene glycol. However, during such catalytic operation, other products and/or streams are generated during the reaction such as water, mixed alcohols, mixed diols, other impurities, and unconverted polyols used as the starting material.
These other products and/or streams may be purified, treated, and/or discarded. However, the presence of various un-wanted compounds in such streams may make discarding such streams problematic. Alternatively, the presence of un-reacted polyols or other polyols in a discarded stream may decrease the overall yield of the desired propylene glycol and/or ethylene glycol and make the process less efficient.
Thus, needs exist for processes to eliminate the presence of any un-wanted compounds in such streams and/or processes to recover any un-reacted polyols or other polyols from such streams such that the un-reacted polyols or other polyols may be converted to the desired propylene glycol and/or ethylene glycol, thus, increasing the efficiency of the overall process.